Introduction: Infective endocarditis (IE) is a life-threatening inflammation of the endocardium most commonly affecting the heart valves. Both left-sided and right-sided involvement of the heart are reported with left-sided pathology leading to more severe complications.
Materials and Methods: This is a case of a patient who was admitted to the hospital with intermittent fever for two months. He was previously treated with antibiotics and showed temporary improvement. The patient underwent surgical aortic valve replacement and ascending aortic prosthesis in 2011 after an acute aortic dissection Stanford type A. A mechanical valve and aortic allograft were used respectively.
Results: Clinical examinations suspected infective endocarditis with unknown location. Different blood tests were performed including a blood culture test which confirmed the presence of alpha haemolytic streptococcus. In similar cases transoesophageal two-dimensional echocardiography (TOE) and transthoracic two-dimensional echocardiography (TTE) play a crucial role in confirming the diagnosis. In this case, however, none of them showed any signs of infective endocarditis. Following the European society of Cardiology (ESC) guidelines - a Positron emission tomography-computed tomography (PET/CT) was performed which showed increased activity in the region around the prosthetic valve and the anastomosis between the allograft and aortic arch. A few more areas were spotted in the middle graft section, all of which indicated an inflammatory process. Signs from other organs indicating infection were registered - diffusely increased splenic (FDG) uptake as well as increased bone-marrow activity. The patient was treated with antibiotics including Amoxiclav and Ciprofloxacin, and his condition quickly improved, consequently he is currently alive. Despite being infrequently used worldwide, that is the first known case in Bulgaria of IE diagnosed with PET/CT.
Conclusion: PET/CT was the only method confirming the diagnosis in this case. It may be used in the future as a non-invasive method for diagnosing IE.
